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Tardos function

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210:, previously used to show that the clique number required exponentially large monotone circuits, also shows that the Tardos function requires exponentially large monotone circuits despite being computable by a non-monotone circuit of polynomial size. Later, the same function was used to provide a 93:. Approximating the Lovász number of the complement and then rounding the approximation to an integer would not necessarily produce a monotone function, however. To make the result monotone, Tardos approximates the Lovász number of the complement to within an additive error of 161: 126: 201: 181: 63:
The Tardos function is monotone, in the sense that adding edges to a graph can only cause its Tardos function to increase or stay the same, but never decrease.
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Tardos used her function to prove an exponential separation between the capabilities of monotone Boolean logic circuits and arbitrary circuits. A result of
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to the approximation, and then rounds the result to the nearest integer. Here
361:(1985), "Lower bounds on the monotone complexity of some Boolean functions", 387: 243:"The gap between monotone and nonmonotone circuit complexity is exponential" 415: 336: 263: 57: 290:, Algorithms and Combinatorics, vol. 27, Springer, p. 272, 77:
for computing the Tardos function requires exponential size.
441:"On Norbert Blum's claimed proof that P does not equal NP" 90: 189: 169: 134: 99: 183:
denotes the number of edges in the given graph, and
287:
Boolean Function Complexity: Advances and Frontiers
195: 175: 155: 120: 48:, the Tardos function is sandwiched between the 8: 36:in 1988 that has the following properties: 405: 188: 168: 147: 138: 133: 112: 103: 98: 56:of the graph. These two numbers are both 91:Grötschel, Lovász & Schrijver (1981) 227: 66:The Tardos function can be computed in 81:To define her function, Tardos uses a 7: 85:for the Lovász number, based on the 83:polynomial-time approximation scheme 233: 231: 14: 203:denotes the number of vertices. 1: 485: 363:Doklady Akademii Nauk SSSR 214:to a purported proof of 156:{\displaystyle m/n^{2}} 121:{\displaystyle 1/n^{2}} 284:Jukna, Stasys (2012), 197: 177: 157: 122: 198: 178: 158: 123: 46:complement of a graph 187: 167: 132: 97: 439:(August 15, 2017), 469:Circuit complexity 416:10.1007/BF02579196 337:10.1007/BF02579273 264:10.1007/BF02122563 208:Alexander Razborov 193: 173: 153: 118: 22:circuit complexity 218:by Norbert Blum. 196:{\displaystyle n} 176:{\displaystyle m} 476: 464:Graph invariants 448: 447: 433: 427: 426: 409: 384: 378: 377: 355: 349: 347: 307: 301: 300: 281: 275: 274: 247: 235: 202: 200: 199: 194: 182: 180: 179: 174: 162: 160: 159: 154: 152: 151: 142: 127: 125: 124: 119: 117: 116: 107: 89:and provided by 87:ellipsoid method 75:monotone circuit 54:chromatic number 484: 483: 479: 478: 477: 475: 474: 473: 454: 453: 452: 451: 435: 434: 430: 407:10.1.1.300.9623 386: 385: 381: 359:Razborov, A. A. 357: 356: 352: 309: 308: 304: 298: 283: 282: 278: 245: 237: 236: 229: 224: 185: 184: 165: 164: 143: 130: 129: 108: 95: 94: 68:polynomial time 30:graph invariant 26:Tardos function 12: 11: 5: 482: 480: 472: 471: 466: 456: 455: 450: 449: 437:Trevisan, Luca 428: 379: 369:(4): 798–801, 350: 331:(2): 169–197, 302: 296: 276: 258:(1): 141–142, 226: 225: 223: 220: 212:counterexample 192: 172: 150: 146: 141: 137: 115: 111: 106: 102: 79: 78: 71: 64: 61: 32:introduced by 13: 10: 9: 6: 4: 3: 2: 481: 470: 467: 465: 462: 461: 459: 446: 442: 438: 432: 429: 425: 421: 417: 413: 408: 403: 399: 395: 394: 393:Combinatorica 389: 383: 380: 376: 372: 368: 364: 360: 354: 351: 346: 342: 338: 334: 330: 326: 325: 324:Combinatorica 320: 319:Schrijver, A. 316: 312: 311:Grötschel, M. 306: 303: 299: 297:9783642245084 293: 289: 288: 280: 277: 273: 269: 265: 261: 257: 253: 252: 251:Combinatorica 244: 240: 234: 232: 228: 221: 219: 217: 213: 209: 204: 190: 170: 148: 144: 139: 135: 113: 109: 104: 100: 92: 88: 84: 76: 72: 69: 65: 62: 59: 55: 51: 50:clique number 47: 43: 42:Lovász number 39: 38: 37: 35: 31: 27: 23: 19: 444: 431: 397: 391: 382: 366: 362: 353: 328: 322: 305: 286: 279: 255: 249: 205: 80: 25: 18:graph theory 15: 400:(1): 1–22, 60:to compute. 458:Categories 315:Lovász, L. 239:Tardos, É. 222:References 34:Éva Tardos 445:in theory 402:CiteSeerX 40:Like the 388:Alon, N. 241:(1988), 52:and the 424:0905147 375:0785629 345:0625550 272:0952004 128:, adds 58:NP-hard 44:of the 422:  404:  373:  343:  294:  270:  216:P ≠ NP 24:, the 246:(PDF) 28:is a 292:ISBN 73:Any 20:and 412:doi 367:281 333:doi 260:doi 16:In 460:: 443:, 420:MR 418:, 410:, 396:, 371:MR 365:, 341:MR 339:, 327:, 317:; 313:; 268:MR 266:, 254:, 248:, 230:^ 414:: 398:7 348:. 335:: 329:1 262:: 256:8 191:n 171:m 149:2 145:n 140:/ 136:m 114:2 110:n 105:/ 101:1 70:.

Index

graph theory
circuit complexity
graph invariant
Éva Tardos
Lovász number
complement of a graph
clique number
chromatic number
NP-hard
polynomial time
monotone circuit
polynomial-time approximation scheme
ellipsoid method
Grötschel, Lovász & Schrijver (1981)
Alexander Razborov
counterexample
P ≠ NP


Tardos, É.
"The gap between monotone and nonmonotone circuit complexity is exponential"
Combinatorica
doi
10.1007/BF02122563
MR
0952004
Boolean Function Complexity: Advances and Frontiers
ISBN
9783642245084
Grötschel, M.

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